Incandesoents



(No Model.)

J. A. CABOT.

PROCESS OF MAKING INGANDESGBNTS.

No. 324,981. Patented Aug. 25, 1885.

EH H k 2 a I l "Q ilnirn STATES ATENT OFFIcE.

JOHN A. CABOT, OF NE\V YORK, N. Y., ASSIGNOR TO THE CABOT ELECTRIC LIGHT AND MANUFACTURING COMPANY OF NEV YORK.

PROCESS OF MAKENG INCANDE SCENTS.

SPECIFICATION forming part of Letters Patent No. 324,981, dated August 25, 1885.

Application filed March 23, 1855. (No nirdel.)

To all whom, it may concern.-

Be itknown that 1, JOHN A. Canor, a citizen ofthe United States, and a resident of New York, in the county of New York and State of New York, have invented a certain newand useful Process for Making Carbon Filaments, of which the following is a specification.

My invention relates to an improved process for making carbon filaments for incair IO descent electric lamps.

In the accompanying drawings, Figure 1 illrutrates a former for molding the filament ii.to the required shape, and Fig. 2 is a diagram view illustrating a part of the process.

h'lyimproved process is as follows: A strand of twisted fiber, preferably silk and of the size and texture known in the market as button-hole twist, is saturated with concentrated coltodion, weak glue, or other simi- 20 la.- carbonaceous tluid, and is then wound upon a former or mold-block and allowed to dry. This lllOld'biOCk is shown in Fig. 1,

wherein the block Ais a stick of wood or similar material, rounded at the ends, of such a a length and width as that when the filament is wound thereon as shown, and cut on both sides ot the block, as at a a, the parts of the filament on either side of the cut will be of a length and shape required for the carbons to be made. I do not confine myself to any particular size or shape for this former. The saturated fiber is allowed to dry snfficiently upon the former to retain its shape, and is then cut as represented, after which a numn ber of the filaments so obtained are placed in a vessel containing boiling linseed-oil or other fixed oil, and. allowed to remain therein till they become carbonized. After removing the filaments from the boiling oil they are strung on wires and placed in a closed iron vesselin the presence of vapor oit' glycerine and subjected to a high temperature, under the influence of which, and by reason of the presence of the glyeerine vapor, they become compact homo- 45 geneous filaments of carbon.

A convenient apparatus for the third and last part of my process is illustrated in Fig. 2

cock g.

of the drawings, wherein B is. a furnace of ordinary construction. C is a muiile therein, and D is an iron box within which the filaments are suspended upon wires E E. F is a metallic vaporizing-retort, theinterior of which is connected bya pipe, f, with the interior of the iron box D. Above the vaporizing-retort F is a reservoir, G, connected with the retort F by a pipe, g, provided with astop-coek, Heat is supplied to the retort F by a fiame,f, so located as to heat the bottom of the retort to a high temperature, and this flame may be obtained from a Bunsen burner or otherwise, as mostconvenient.

In operation the box 1) being filled with filaments suspended as described, and placed within the furnace B, and the retort F being heated, a supply of glycerine is placed in the reservoir G, and a portion of this glyccrine is allowed to tlow into the retort by turning the The glycerine thus admitted into the retort is vaporized and passes over into the box D, where it surrounds the filaments.

To insure the circulation of the vaporized glyccrine from the retort into the box D, a small vent-hole, b, is made through the top of said box.

. I do not wish to claim, broadly, the use of oils in the manufacture of carbons; nor do I claim, broadly, the method herein described of shaping the filaments on a former.

\ hat I do claim is The herein-described process of making carbon filaments, consisting in saturating twisted fibrous filaments with concentrated collodion or similar material,molding the said filaments into shape, carbonizing the same in boiling fixed oil, and afterward subjecting them to intense heat in the presence of vapors from the decomposition of glycerine.

Signed at Trenton, New Jersey, the 17th day of March, 1885.

JOHN A. CABOT.

XVit-ncsses:

T. E. BAKER, G120. W. MAcPn'nnsox, 

